Fastening structure for securing stator of motor

ABSTRACT

A fastening structure for securing a stator of a motor includes a sleeve with a cut portion formed thereon and a fastener. The fastener is composed of a position section and an engaging section, wherein the engaging section engages with the cut portion and the position section presses on the top surfaces of the coil bobbin of the stator.

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 10/437,145, filed on May 12, 2003 now U.S. Pat. No.6,759,772. The entire contents of the related application areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a fastening structure for the stator of a motorand, in particular, to a fastening structure for the stator of a motor,which can prevent the stator from falling off by means of a fastener

2. Description of the Related Art

The stator of a motor is liable to fall off if the assembly strength ofthe motor is not high enough to withstand the continuous vibrationduring a long period of operation. In view of this, if one can provide afastening structure compatible with conventional parts of a motor, theassembly strength of the motor can be enhanced significantly at lowcost.

BRIEF SUMMARY OF THE INVENTION

In view of the above, an objective of the invention is to provide afastening structure for securing the stator of a motor, which enhancesthe assembly strength of a motor by a fastener engaging with a sleeveand thus the stator can be tightly secured to the motor duringoperation.

Another objective of the invention is to provide a fastening structurefor securing the stator of a motor, which can protect the coil by aspecial design of a fastener.

According to an embodiment of the invention, a fastener includes aposition section and an engaging section. The two sides of the positionsection of the fastener are designed to respectively touch the sleeveand the top surface of the coil bobbin. The sleeve is machined on itsside surface to form a cut portion at a specific distance from the topsurface of the sleeve, which is designed to be substantially the same asthe distance from the position section to the end surface of theengaging section. Therefore, when the engaging section is inserted intothe cut portion, the two sides of the position section tightly pressagainst the sleeve and the top surface of the coil bobbin so as toenhance the assembly strength and establish a firm connection.

According to another embodiment of the invention, one side of theposition section adjacent to the coil bobbin is extended to the extentthat it can cover the whole coil of the stator, which prevents thefriction between the coil and the rotor so as to protect the coil.

According to still another embodiment of the invention, a first cutportion is formed on the sleeve, and a second cut portion is formedinwardly at the bottom of the first cut portion. The first cut portionand second cut portion together form an L-shaped cut portion toaccommodate the engaging section of the fastener. When the engagingsection is inserted into the L-shaped cut portion of the sleeve, the twosides of the position section press tightly against the sleeve and a topsurface of the silicon steel sheet covering the coil to secure thestator of the motor.

Furthermore, the fastener may be of a circular structure, an arcstructure or a combination of a plurality of arc structures having thesame center and radius.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective cross sectional view showing a fastener of thefastening structure according to an embodiment of the invention.

FIG. 2 is a sectional view showing the connection of the fastener andcomponents of a motor according to an embodiment of the invention.

FIG. 3 is an enlarged cross-section of the fastener shown in FIG. 2,which illustrates more clearly the design of the fastening structureaccording to the embodiment of the invention.

FIG. 4 is a sectional view showing the connection of the fastener andthe components of the motor according to another embodiment of theinvention.

FIG. 5 is an enlarged cross-section of the fastener shown in FIG. 4.

FIG. 6 is a sectional view showing another motor, with the arrangementof components different from that of the motor, incorporating thefastener structure of the invention.

FIG. 7 is an enlarged cross-section of the fastener shown in FIG. 6.

FIG. 8 is a perspective cross sectional view showing a fasteneraccording to still another embodiment of the invention.

FIG. 9 is a perspective view showing another modification of thefastener structure according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The fastening structure for securing the stator of a motor according toan embodiment of the invention will be described hereinbelow withreference to the accompanying drawings, wherein the same referencenumbers refer to the same components.

FIG. 1 is a perspective cross sectional view showing a fastener 10 ofthe fastening structure according to an embodiment of the invention. Asshown in FIG. 1, the fastener 10 with a circular shape is composed of aposition section 10A and an engaging section such as a hook section 10B,and both sections may be integrally formed by molding. Each of the twosides of the position section 10A has a particular thickness thatdepends on which component of the motor is to be assembled with. Thehook section 10B has an end surface P, and the distance h from theposition section 10A to the end surface P of the hook section 10B is asindicated in FIG. 1.

FIG. 2 is a sectional view showing the connection of the fastener 10 andcomponents of a motor 1 according to an embodiment of the invention.FIG. 3 is an enlarged cross-section M of the fastener 10 shown in FIG.2, which illustrates more clearly the design of the fastening structureaccording to the embodiment of the invention.

As shown in FIG. 2, the stator 16 of the motor 1 includes a coil bobbin14 and a coil 18. In this embodiment, the two sides of the fastener 10connect a sleeve in the motor 1, such as a copper sleeve 12, and thecoil bobbin 14 of the stator 16, respectively. More specifically, thetwo sides of the position section 10A of the fastener 10 are designed torespectively touch the copper sleeve 12 and the top surface of the coilbobbin 14 as shown in FIG. 3. The copper sleeve 12 is machined on itsside surface to form a cut portion such as a notch 12A at a distance tfrom its top surface, the distance t is designed to be substantially thesame as the distance h from the position section 10A to the end surfaceP. Therefore, when the hook section 10B is inserted into the notch 12A,the two sides of the position section 10A tightly press against thecopper sleeve 12 and the top surface of the coil bobbin 14 so as toestablish a firm connection.

The vibration during the operation of the motor may cause the stator 16to fall off due to an upward force acting thereon. Therefore, thefastening structure of this embodiment can solve the problem in the mosteffective way. By inserting the end surface P of the hook portion 10Binto the notch 12B, the resulting force with which the position section10A presses against the coil bobbin 14 counteracts the upward force thatacts on the stator 16 at point Q during vibration. Therefore, theassembly strength can be enhanced significantly, and the stator 16 canthus be tightly secured to the motor.

FIG. 4 is a sectional view showing the connection of the fastener 20 andthe components of the motor 1 according to another embodiment of theinvention. FIG. 5 is an enlarged cross-section N of the fastener 20shown in FIG. 4.

In this embodiment, the side of the position section 20A adjacent to thecoil bobbin 14 is extended to the extent that it can cover the wholecoil 18 of the stator 16, which prevents the friction between the coil18 and the rotor 22 so as to protect the coil 18.

FIG. 6 is a sectional view showing another motor 2, with the arrangementof components different from that of the motor 1, incorporating thefastener structure of the invention. FIG. 7 is an enlarged cross-sectionO of the fastener 30 shown in FIG. 6. As shown in FIG. 6, the motor 2includes a sleeve such as a copper sleeve 32 and a silicon steel sheet34 for securing a coil 36, with the copper sleeve 32 touching thesilicon steel sheet 34. As shown in FIG. 7, the copper sleeve 32 of thisembodiment is formed with a first cut portion having a width t1 and aheight h, and then inwardly forms with a second cut portion with a deptht2 at the bottom of the first cut portion. The first cut portion andsecond cut portion together form an L-shaped cut portion on the sidesurface of the copper sleeve 32 to accommodate the hook section 30B ofthe fastener 30. When the hook section 30B is inserted into the L-shapednotch, the two sides of the position section 30A respectively pressagainst the copper sleeve 32 and the top surface of the silicon steelsheet 34 so as to secure the stator of the motor 2.

In view of the above, the invention can be implemented in various kindsof motors each having different arrangement of components simply bychanging the type of the cut portion formed on the sleeve and modifyingthe shape of the fastener. Although the motor 1 and the motor 2 are bothouter-rotor motors, one having ordinary skill in the art shouldunderstand that the invention can be also implemented in an inner-rotormotor.

FIG. 8 is a perspective cross sectional view showing a fastener of thefastening structure according to still another embodiment of theinvention. The shape of the fastener according to the invention includesbut is not limited to a circular shape. For example, as shown in FIG. 8,a pair of arc structures 42 and 44 having the same center and radius canbe provided between the sleeve and the stator to achieve the objectiveof securing the stator and protecting the coil. Of course, one can onlyprovide a single arc structure between the sleeve and the stator.

Moreover, FIG. 9 shows another modification of the fastener structure,where the position section 50A of the fastener 50 has a circular shapewhile the hook section 50B thereof is composed of a plurality of arcstructures having the same center and radius. It is understood that thenumber of the arc structures shown in FIG. 8 and FIG. 9 is not limited,but to satisfy the demand for a firm connection.

While the invention has been described by way of example and in terms ofthe preferred embodiment, it should be understood that the invention isnot limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements aswould be apparent to those skilled in the art. Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

1. A fastening structure for securing a stator of a motor, comprising: a sleeve having a cut portion; and a fastener having a position section and an engaging section, the engaging section being inserted into the cut portion, and the position section pressing against the top surface of the stator and the sleeve.
 2. The fastening structure according to claim 1, wherein the side of the position section pressing against the stator extends to cover the coil of the stator.
 3. The fastening structure according to claim 1, wherein the fastener has a circular shape.
 4. The fastening structure according to claim 1, wherein the fastener is in the shape of an arc.
 5. The fastening structure according to claim 1, wherein the fastener is a combination of a plurality of arc structures having the same center and radius.
 6. The fastening structure according to claim 1, wherein the position section of the fastener has a circular shape and the engaging section thereof is composed of a plurality of arc structures having the same center and radius.
 7. The fastening structure according to claim 1, wherein the fastener is integrally formed by molding.
 8. The fastening structure according to claim 1, wherein the sleeve is a copper sleeve.
 9. The fastening structure according to claim 1, wherein the engaging section is a hook section.
 10. The fastening structure according to claim 1, wherein the cut portion is formed as a notch.
 11. A fastening structure for securing a stator of a motor, the stator having a coil bobbin, the fastening structure comprising: a sleeve having a cut portion formed laterally and inwardly on the side surface of the sleeve, the cut portion keeping a specific distance from the top surface of the sleeve; and a fastener having a position section and an engaging section, the engaging section being inserted into the cut portion, and the position section pressing against the top surface of the stator and the sleeve.
 12. The fastening structure according to claim 11, wherein the fastener has a circular shape.
 13. The fastening structure according to claim 11, wherein the fastener is in the shape of an arc.
 14. The fastening structure according to claim 11, wherein the fastener is a combination of a plurality of arc structures having the same center and radius.
 15. The fastening structure according to claim 11, wherein the fastener is integrally formed by molding.
 16. The fastening structure according to claim 11, wherein the sleeve is a copper sleeve.
 17. The fastening structure according to claim 11, wherein the engaging section is a hook section.
 18. The fastening structure according to claim 11, wherein the cut portion is formed as a notch.
 19. A fastening structure for securing a stator of a motor, the stator having a silicon steel sheet to secure a coil of the motor, the fastening structure comprising: a sleeve having a first cut portion and a second cut portion formed inwardly at the bottom of the first cut portion, the first cut portion and the second cut portion together forming an L-shaped cut portion; and a fastener having a position section and an engaging section, the engaging section being inserted into the L-shaped cut portion, and the position section pressing against the top surface of the silicon steel sheet and the sleeve.
 20. The fastening structure according to claim 19, wherein the fastener has a circular shape. 